Shaft straightener



Filed May 31, 1960 INVENTOR GLENN A. DELF ATTORNEYS 3,960,993 Patented Oct. 30, 1962 3,0603% SHAFT STRAl-QHTENER Glenn A. Delf, St. Louis, Mo., assignor to Atias Tool & Manufacturing Co, St. Louis, M0., a corporation of Missouri I Fiied May 31, 1960, Ser. No. 32,758 9 Claims. (Cl. 15332) This invention relates generally to a shaft straightener, and more particularly to an improved apparatus of this type adapted to straighten a shaft without removing it from the engine.

A common cause of damage to the engines of rotary lawn mowers is the bending of their crankshafts, usually caused by the blades striking a stone or other heavy object. Heretofore, repair operations involved the step of removing the shaft from the engine, thus resulting in a sometimes diflicult and time-consuming procedure, the expense of which often exceeded the cost of a new shaft. The present invention affords an apparatus for straightening a shaft without removing it from the engine, and in a simple manner that requires little or no skill on the part of the operator.

An important object is achieved by the provision of means for mounting an engine on a base so that the driving end of the crankshaft extends into a well between a fixed anvil and a movable block, and by the provision of means for reciprocally moving the block toward or away from the shaft incident to straightening the shaft between the anvil and block.

Another important object is realized by the disposition of the anvil and block in spaced depthwise relation in the well, the anvil engaging one side of the shaft closely adjacent the point where the shaft emerges from the crankcase, and the block engaging the opposite side of the shaft adjacent its outermost end upon actuation of the block in one direction, the fixed anvil operating to hold the shaft at a reference axis while the block bends the shaft straight along such reference axis.

Still another important object is obtained by the provision of a feeler that contacts the shaft, the feeler being operatively connected to an indicating means such as a dial gauge adapted to indicate the amount of deformation or bend of the shaft from a reference axis defined by the engagement of the shaft with the fixed anvil.

Other important advantages are realized in that the feeler contacts the shaft on the same side as the anvil yet directly opposite the block so as to indicate the maximum bend from the reference axis in the direction of the movable block upon rotation of the shaft, thereby assuring that the shaft is positioned at all times such that the block is effective upon actuation to cause the greatest deflection back to perfect alignment along the reference axis.

Yet another important object is achieved by the provision of a hydraulic ram to actuate the movable block in one direction towards the shaft, thus increasing the efliciency of the apparatus. Means such as springs are utilized to return the block to its retracted position upon release of hydraulic pressure on the ram.

Another important objective is realized by providing substantially V-shaped notches in the anvil and movable block adapted to receive opposite sides of the shaft during the bending operation. It is advantageous to define the notches by walls inclined relative to the reference shaft axis so that an outermost margin on each of the anvil and movable block engages the shaft.

An important object is to provide a shaft straightener that is simple and durable in construction, economical to manufacture, efficient in operation, and which can be readily operated by any one with only a minimum of instruction.

The foregoing and numerous other objects and advantages of the invention will more clearly appear from the following detailed description of a preferred embodlment, particularly when considered in connection with the accompanying drawing, in which:

FIG. 1 is a top plan view of the shaft straightener;

'FIG. 2 is a cross-sectional View of the straightener 'as seen along a vertical, longitudinal plane passed through the center of FIG. 1, and

FIG. 3 is an end elevation-a1 view of the shaft straightener.

Referring now by characters of reference to the drawing, it is seen that the apparatus includes a base generally indicated at 10 formed by a pair of spaced, parallel side walls 11 and 12, a plurality of transverse partitions 13, 14, and 15, and bottom walls 16 and 17, as is best seen in FiG. 2. 'Ihe side walls 11 and 12, together with the transverse partitions 13 and 14 define a well that is open at the top and at the bottom.

At each end of the base 10 are a pair of laterally extending, opposed legs 21. These legs 21 are attached to a stand referred to at 22 and is best shown in FIG. 3. The stand 22 serves to support the shaft-straightening apparatus on a subjacent supporting surface such as a floor. Under some conditions, it is desirable to support the apparatus on a table for which a suitable structure can be conveniently supplied.

Mounted on top of base 10, and more particularly attached to the top of side Walls 11 and 12, is a circular ring 23 constituting a platform. As is best seen in FIG. 1, a plurality of apertures 24 are provided in ring 23, such apertures 24 serving to mount an engine on top of the ring 23. When the engine is attached to the ring 23, the driving end 25 of the crankshaft extends downwardly into the well 20 formed in the base 10.

An anvil 26 is fixed by screws 27 to the top of base 10. More particularly, the anvil 26 is located at the top of base It and at one side of well 20 adjacent the transverse partition 14. The anvil 26 includes a substantially V-s'haped notch 30 adapted to receive one side f the shaft 25 closely adjacent the point where the shaft emerges from the crankcase of the engine. The notch 30 is defined by a wall 31 inclined relative to the shaft axis so that the outermost margin of the anvil 26 defining t e notch 30 engages the shaft 25.

For reasons which will later appear, the engagement of the shaft 25 with the fixed anvil 26 defines a reference axis 32 (FIG. 2) along which the shaft 25 is to be aligned or straightened.

Located in the other side of well 20 and spaced below anvil 26 along the shaft 25 or reference axis 32, is a block 33. Provided in the front face of block 33 is a substantially V-shaped notch 34 adapted to receive the other side of shaft 25 when the block 33 is moved toward the reference axis 32. The notch 34 is defined by a Wall 35 inclined with respect to the reference axis 32 or shaft 25 so as to provide an outermost margin adapted to engage the lowermost end of shaft 25.

A hydraulic mechanism is operatively connected to block 33 to reciprocate the block 33 toward and away from shaft 25. Specifically, the mechanism includes a cylinder 36 threadedly attached to partition 13. Slidably mounted within cylinder 36 is a coacting piston 37, the outermost end of piston 37 being attached to block 33.

A hydraulic pump 40, shown in FIG. 3, is attached to stand 22 and is operated by a hand lever 41. The pump 40 is operatively connected to cylinder 36 by hose 42. Upon actuation of pump 40 by handle 41, hydraulic pressure is exerted through hose 42 into the outermost end of cylinder 36, and hence against the innermost end of piston 37, the hydraulic pressure causing the piston 37 and the block 33 to move in a direction toward the shaft 25.

As is best seen in FIG. 1, the block 33 is provided with a pair of sockets 43, one such socket 43 being located at each side of notch 34. A pair of bolts 44 are attached to partition .14 and extend inwardly of well 20. One of the bolts 44 is aligned with each of the sockets 43. Mounted around the stem of each bolt 44 is a compression spring 45, one end of each spring 45 abuts the partition 14, while the opposite end is received in socket 43 and abuts block 33.

The hydraulic mechanism is utilized to move the block 33 in one direction, i.e., toward and into engagement with the shaft 25. Upon release of the hydraulic pressure within cylinder 36, the springs 45 act to move the block 33 toward a retracted position away from shaft 25.

Slidably mounted within aligned apertures 46 formed in base partitions 14 and 15 is a reciprocating rod 47, the rod 47 constituting a feeler or follower as will be subsequently explained. One end of rod 47 engages the outermost end of shaft on the same side as anvil 26 and directly opposite the block 33. Means such as a spring (not shown) is provided tending to urge the end of rod 47 into engagement with shaft 25 at all times. The opposite end of rod 47 is operatively connected to an indicating mechanism such as a dial gauge 50 that is calibrated to indicate the position of rod 47.

'For example, when the shaft 25 is straight and vertically aligned along the reference axis 32, the end of rod 47 engaging the shaft is located in its zero position relative to the reference axis 32, and such zero position is indicated by the pointer on a calibrated scale provided on gauge 50. If the outermost end of shaft 25 is inclined relative to the reference axis 32 in a direction toward the movable block 33, the rod 47 engaging such shaft 25 will be ofiset to one side of its zero position and will cause a deflection of the gauge pointer in one direction from the pointers zero position. Similarly, when the shaft 25 is bent from the reference axis 32 in a direction away from the movable block, the rod 47 engaging the shaft 25 will be offset to the other side of the zero position and will cause a deflection of the pointer in the opposite direction from the pointers zero position indicated on gauge 50. it is now understood that the rod 47 and the gauge 50 indicate the direction of shaft bend from the reference axis 32, and in addition indicate the amount of such bend.

It is thought that the operation and functional advantages of the shaft straightener have become fully apparent from the foregoing detailed description of parts, but for completeness of disclosure, the straightening of a shaft is hereinafter briefly set forth.

First, the engine is attached to platform ring 23 so that the shaft 25 extends downwardly into well 2% and is received by the V-shaped notch formed in anvil 26. The outermost margin of anvil 26 engages the one side of shaft closely adjacent the point Where the shaft emerges from the crankcase of the engine. As stated previously, the engagement of shaft 25 with anvil 26 determines the reference axis 32.

While the engine is being mounted, the block 33 is maintained in a retracted position out of engagement with shaft 25 under the influence of compression springs 45. It will be assumed that the'hydraulic pressure provided by pump 40 is released at this stage of the operation.

The shaft 25 is rotated until the greatest deflection from reference axis 32 is obtained in the direction of movable block 33. This condition becomes readily apparent by reading gauge that is actuated by rod 47 riding on the lower end of shaft 25. When the gauge 50 indicates the greatest amount of deflection in the direction of block 33, the hydraulic pump 40 is actuated to exert a hydraulic pressure in cylinder 36, thereby moving the block 33 into engagement with shaft 25. Upon controlling the amount of pressure exerted on movable block 33, the shaft 25 is bent back into alignment with the reference axis 32 between the block 33 and anvil 26.

As the shaft 25 is deflected or straightened, the amount of straightening is readily indicated by gauge 50. For example, as the shaft 25 approaches the reference axis 32, the rod 47 engaging the shaft 25 is moved toward its zero position which is shown on gauge 50. When the shaft 25 is deflected back to the zero position as determined by the rod 47 and gauge 50, the hydraulic pressure provided by pump 40 is released, thereby allowing the compression springs 45 to retract the block 33 away from the shaft 25.

The shaft 25 is then rotated until any additional shaft bend, if any, is in the direction of movable block 33 as will be readily determined by reading of the gauge 50 in the manner previously described. Then, the hydraulic ram is actuated to force movable block 33 into engagement with shaft 25 so as to bend the shaft 25 straight along the reference axis 32. This procedure is repeated as many times as is necessary until the shaft 25 is completely straightened.

Although the invention has been described by making detailed reference to a single preferred embodiment, such detail is to be understood in an instructive, rather than in any restrictive sense, many variants being possible within the scope of the claims hereunto appended.

I claim as my invention:

1. A shaft straightener comprising a base, a platform on the top of said base adapted to mount an engine, the platform being provided with an opening, the base being provided with a well aligned with said opening into which the shaft of the engine extends, an anvil fixed to the top of said base and adapted to engage one side of the shaft, a block movably mounted on said base and spaced elow said anvil axially along said shaft, and means for moving the block toward or away from the opposite side of said shaft, the block selectively engaging the shaft to straighten said shaft between the anvil and block.

2. A shaft straightener comprising a base, a platform on the 'base adapted to mount an engine, the base being provided with a well into which the shaft of the engine extends, an anvil fixed to said base at the entrance to the well and adapted to engage one side of the shaft closely adjacent the point where the shaft emerges from the crankcase of the engine to provide a reference axis, a movable block mounted on said base and spaced from said anvil along said reference axis, and means for moving the block toward or away from the opposite side of said shaft, the block selectively engaging the shaft to straighten said shaft between the anvil and block along said reference axis, the anvil and block each being provided with a substantially V-shaped notch into which the shaft interfits, said notches being defined by a wall inclined relative to the reference axis to provide an outermost margin on each of the anvil and block that is adapted to engage said shaft.

3. A shaft straightener comprising a base, the base being provided with a well, a platform having an opening aligned with said well, the platform being secured on the top of said base and adapted to mount an engine so that its shaft extends through said opening into said Well, an anvil fixed to the top of said base at one side of said well and adapted to engage one side of the shaft closely adjacent the point where the shaft emerges from the crankcase of the engine, the engagement of the shaft and anvil defining a reference axis, a block in the other side of said well and spaced along the reference axis below said anvil, a hydraulic ram attached to said base and connected to said block, means for operating said ram to force said block into engagement with the other side of said shaft adjacent the outermost end of said shaft so as to straighten the shaft along the reference axis between the anvil and block.

4. The combination and arrangement of elements as recited above in claim 3, but further characterized in that the anvil and block each are provided with a substantially V-shaped notch adapted to receive the shaft, said notches being defined by walls that are inclined relative to the reference axis to provide an uppermost margin on the anvil and a lowermost margin on the block which engage said shaft.

5. A shaft straightener comprising a base, the base being provided with a well, a platform on the top of said base adapted to mount an engine so that its shaft extends into said well, the platform having an opening aligned with the well, an anvil fixed to the top of said base at one side of said well and adapted to engage one side of said shaft closely adjacent the point where the shaft emerges from the crankcase of the engine, the engagement of the anvil with the shaft defining a reference axis, a block reciprocally mounted on said base and located in said well, the block being spaced along the reference axis below said anvil and adapted to engage the opposite side of said shaft adjacent the outermost end of said shaft, means for reciprocally moving said block toward or away from said shaft, the block selectively engaging the shaft of straighten the shaft along the reference axis between the anvil and block.

6. The combination and arrangement of elements as recited above in claim 5, but further characterized in that t the means for reciprocating the block includes a hydraulic ram mounted on the mase and attached to said block, means for actuating said hydraulic ram in one direction to move the block into engagement with said shaft, and spring means attached to said block tending to urge the block into retracted position away from said shaft upon operative release of said hydraulic ram.

7. In a shaft straightener comprising a base including spaced side walls and spaced interconnecting partitions providing a well therebetween, a platform on the top of said base adapted to mount an engine, the platform being provided with an opening aligned with said well into which the shaft of the engine extends, an anvil fixed to the top of said base adjacent one partition, the anvil extending into said -Well to engage one side of the shaft closely adjacent the point where the shaft emerges from the crankcase of the engine, a cylinder mounted to the other partition and a piston operable in said cylinder, a block attached to said piston and movable into said well below said anvil to engage the opposite side of said shaft, and fluid means connected to said cylinder for actuating said piston to move the block into engagement with said shaft incident to straightening the shaft between the anvil and block.

8. A shaft straightener comprising a base, a platform on the base adapted to mount an engine, the base being provided with a well into which the shaft of the engine extends, an anvil fixed to said base at the entrance to the well on one side of the Well to engage one side of the shaft closely adjacent the point where the shaft emerges from the crankcase of the engine, a block in the other side of the Well and spaced from said anvil, a hydraulic ram attached to said base and connected to said block, means for operating said ram to force said block into engagement with the other side of said shaft adjacent the outermost end of said shaft so as to straighten the shaft between the anvil and block, and spring means carried by the block on each side of the shaft, the spring means operatively engaging the base and tending to urge the block into retracted position away from said shaft upon operative release of said hydraulic ram.

9. A shaft straightener comprising a base including spaced side Walls and spaced interconnecting partitions providing a Well therebetween, a platform on the top of said base adapted to mount an engine, the platform being provided with an opening aligned with said Well into which the shaft of the engine extends, an anvil fixed to the base adjacent one partition on one side of the well, the anvil extending into said well to engage one side of the shaft closely adjacent the point where the shaft emerges from the crankcase of the engine, a cylinder carried by the other partition, a piston operable in said cylinder, a block attached to said piston and located in the other side of said Well below said anvil, fluid means connected to said cylinder for actuating the piston to move the block toward the opposite side of said shaft to engage the shaft and straighten the shaft between the anvil and block, the block being provided with a socket on each side of said shaft, a compression spring located in each of said sockets, and means connecting each of said springs With the said one partition so that said springs tend to urge the block into retracted position away from said shaft upon operative release of the piston by the fluid means.

References Cited in the file of this patent UNITED STATES PATENTS 1,308,501 Littell July 1, 1919 1,620,260 Kellogg Mar. 8, 1927 2,310,151 Pope Feb. 2, 1943 2,371,464 Olsson Mar. 13, 1945 2,3 89,206 McKinney et al Nov. 20, 1945 2,426,340 Bush Aug. 26, 1947 

